Electrical drive system for earth moving machinery

ABSTRACT

An electrical drive system that modifies operation between that of a generator and a motor based on changes in operation of a tractor and machine scraper in order to charge the electrical drive system when the machine scraper is empty or being unloaded and to power the drive of the machine scraper when the machine scraper is cutting and loading a bowl of the machine scraper and during the transport of the load from the location of the cutting and loading.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from Provisional Application No. 63/238,611 filed Aug. 30, 2021, and Provisional Application No. 63/277,871 filed Nov. 10, 2021, the contents of these applications are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

This disclosure generally relates to an electrical drive system for earth moving machinery. More specifically, the disclosure relates to an electrical drive system for a machine scraper towed by a tractor.

Machine scrapers are used in earth moving to cut into the ground and collect a fill of dirt or other material. During a cut, a scraper blade of the machine scraper is lowered and angled to be driven into the ground in a cut. Thereafter, the machine scraper is driven forward to cleave off an upper layer of the ground, which is pushed into a bowl of the machine scraper during the cut. After the cut, the loaded material is transported to a different location where the loaded material is ejected from the bowl of the machine scraper.

Conventional machine scrapers come in two primary forms. The first is a machine scraper that is connected to or hitched to a tractor and then towed around a project site during the cut, transport, and fill. Due to limitations of the tractor, inadequate force is applied during the cut, which increases the time it takes for a cut to take place and often leads to the cut collecting a smaller load. In short, the tractor by itself makes inefficient use of the machine scraper.

To remedy this issue, it is commonplace to use what is known as a push cat (or push dozer). During a push dozer, one or more bulldozers travel behind the scraper and then push the scraper during the cut to speed up the duration of the cut and to increase the size of the load into a bowl of the scraper.

Although beneficial, the push dozer approach has several drawbacks. For one, the method requires three pieces of machinery to be operated: a machine scraper, a tractor, and at least one bulldozer. This increases the amount of machinery required for use on a job site, which naturally increases cost. Similarly, the addition of at least one bulldozer requires an additional operator, which further increases costs. As both operators must work in conjunction to make use of this methodology, the operators must coordinate to successfully accomplish the cut. As a result, it is possible for the operator of the bulldozer to push too little or too much, each of which present a problem by either limiting the additional force provided by the bulldozer or exceeding the force needed, which unnecessarily wears on the bulldozer, the machine scraper, and the tractor.

An alternative to this approach is the use of a self-contained scraper that is not towed by a tractor and instead is operated as its own standalone machine. Although this limits the need for a separate bulldozer in many instances, it is also problematic for multiple reasons. By excluding the use of a tractor, costs are increased as the tractor is not made use of and in its place is the self-contained scraper that is more expensive than a machine scraper that is simply towed. Additionally, as the system is self-contained, wear and tear eventually lead to replacement of the entire machine—engine and scraper, which is more costly.

Thus, it is a primary aspect of this disclosure to provide an electrical drive system that improves upon the art.

Another aspect of this disclosure is to provide an electrical drive system that eliminates the need for a push dozer methodology of operation.

Yet another aspect of this disclosure is to provide an electrical drive system that reduces operational costs of heavy machinery, including a machine scraper and those towed by a tractor.

Another aspect of this disclosure is to provide an electrical drive system that reduces the number of machines required to complete a project.

Yet another aspect of this disclosure is to provide an electrical drive system that reduces the number of operators required to complete a project.

Another aspect of this disclosure is to provide an electrical drive system that retrofits to an existing machine scraper.

Yet another aspect of this disclosure is to provide an electrical drive system that retrofits to an existing bowl of a machine scraper.

Another aspect of this disclosure is to provide an electrical drive system that increases the torque of a towed machine scraper during a cut and transport.

Yet another aspect of this disclosure is to provide an electrical drive system that increases the operational life of a machine scraper and a tractor.

Another aspect of this disclosure is to provide an electrical drive system that operates for a full workday without need for a plugged charge.

Yet another aspect of this disclosure is to provide an electrical drive system that matches the actual ground speed of a tractor with the ground speed of a machine scraper.

Another aspect of this disclosure is to provide an electrical drive system that provides consistent power, including behind a cutting edge.

Yet another aspect of this disclosure is to provide an electrical drive system that reduces negative environmental impacts of machine scraper operation.

Another aspect of this disclosure is to provide an electrical drive system that allows for a quick swap of battery packs to limit down time should a battery pack be exhausted.

These and other aspects, features, and advantages of the invention will become apparent from the specification and claims.

SUMMARY OF THE INVENTION

The disclosure provides various aspects of an electrical drive system for earth moving machinery.

One aspect of the disclosure, broadly described herein relates to an electrical drive system, including a battery pack; an electrical drive device in electrical communication with the battery pack; a power control system connected to the electrical drive device; a power conditioning circuit connected to the electrical drive device and the power control system; a powered axle connected to the electrical drive device; wherein the power control system and electrical drive device are configured to operate as a generator through passive rotation of the powered axle to create power that is stored in the battery pack; wherein the electrical drive device and the power control system are configured to operate as a motor by providing power stored in the battery pack to the powered axle; and wherein the electrical drive device and the power control system are configured to operate in an empty phase, a cutting/loading phase, a transport phase, and a fill/dump phase.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system further including a tractor control system and a scraper control system; wherein the tractor control system and the scraper control system are configured to transmit information from at least one sensor with the power control system; and wherein the power control system is configured to command the electrical drive device to operate as a generator and a motor based on information received from the tractor control system and the scraper control system.

Another aspect of the disclosure, broadly described herein relates to an electrical system further including the tractor control system having at least one sensor selected from a group consisting of a tractor speed sensor configured to sense a speed registered by a tractor but not an actual ground speed, a commanded gear sensor configured to sense a gear that the tractor is currently in, an output shaft speed sensor configured to sense the speed of an output shaft of the tractor, an engine torque sensor configured to sense a torque output of an engine of the tractor, an engine speed sensor configured to sense a speed of the engine of the tractor, a coolant temperature sensor configured to sense a coolant temperature of the engine of the tractor, an oil pressure sensor configured to sense an oil pressure of a hydraulic system of the tractor, an estimate ground speed sensor that is configured to calculate an actual ground speed of the tractor that does not account for environmental changes and slippage, and an actual ground speed sensor configured to determine the actual ground speed of the tractor.

Another aspect of the disclosure, broadly described herein relates to an electrical system further including the scraper control system having the at least one sensor selected from a group consisting of an apron sensor configured to sense and control a position of an apron of a machine scraper, a cutting edge sensor configured to sense and control a position a scraper blade of a machine scraper and an angle of a cutting edge of the scraper blade, a load sensor configured to sense the weight of a load carried in a bowl of a machine scraper, and a powertrain cooling system sensor.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system further including a differential, a final drive, a wheel, and a tire connected to the powered axle; wherein the pair of spindles are connected to opposing sides of the differential.

Another aspect of the disclosure, broadly described herein relate to an electrical drive system further including a spacer positioned between the differential and at least one of the pair of spindles, wherein the spacer is configured to adjust the width of the powered axle.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system further including the powered axle extending through a rearward housing of a bolt on rear tube; wherein the battery pack, the electrical drive device, the power control system, and the power conditioning device are mounted to the powered axle within the rearward housing.

Another aspect of the disclosure, broadly described herein relate to an electrical drive system wherein powered axle is retrofitted to the built on rear tube in a position and replacement of a dummy axle.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system wherein the battery pack is positioned over a centerline of the powered axle extending axially along a length of the powered axle.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system further including at least one cable connecting the battery pack to the electrical drive device; wherein the battery pack is positioned immediately above the electrical drive device.

Another aspect of the disclosure, broadly described herein relates to an electrical drive device further including a differential directly coupled to the electrical drive device.

Another aspect of the disclosure, broadly described herein relates to an electrical drive device wherein the electrical drive device and the power control system are positioned to a rear of the differential and behind a centerline of the powered axle extending axially along a length of the powered axle.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system further including a machine scraper having a bowl connected to the bolt on rear tube; the bowl having an apron, an ejector, and a scraper blade having a cutting edge; and the machine scraper connected to a tractor.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system wherein the power control system is configured to command the electrical drive device to operate as a motor to provide power to the powered axle to match the speed of the machine scraper to an actual speed of the tractor.

Another aspect of the disclosure, broadly described herein relates to an electrical system wherein the electrical drive device and the power control system are configured to operate as a motor under a predefined speed and a predefined gear of the tractor, wherein the predefined speed varies based on the predefined gear.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system wherein the power control system is configured to command the electrical drive device to operate in the empty phase, the cutting/loading phase, the transport phase, and the fill/dump phase based on a condition selected from a group consisting of a condition of the tractor and a condition of the machine scraper.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system wherein when the power control system and electrical drive device operate in the empty phase and the fill/dump phase, the powered axle rotates without the electrical drive device providing power, and the electrical drive device operates as a generator by putting drag on an engine of the tractor by way of the powered axles to charge the battery pack; and wherein when the power control system and electrical drive device operate in the cutting/loading phase and the transport phase, the power control system commands the electrical drive device to operate as a motor to provide power to the powered axle.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system wherein the condition of the tractor is selected from a group consisting of an actual speed of the tractor, a gear of the tractor, an output shaft speed of the tractor, an engine torque of the tractor, a calculated speed of the tractor, and an error fault of a tractor control system of the tractor.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system wherein a discharge from the battery pack is higher in the cutting loading phase than the transport phase.

Another aspect of the disclosure, broadly described herein relates to the electrical drive system wherein the power conditioning circuit is configured to determine that the battery pack is at a buffer and to command the electrical drive device to operate in a low-torque mode to supply only an amount of torque necessary to overcome a rolling resistance of a wheel.

Another aspect of the disclosure, broadly described herein relates to an electrical drive system wherein the electrical drive device is configured to provide regenerative braking by drawing down the power to the powered axle upon the tractor braking.

This has outlined, rather broadly, the features, advantages, solutions, and benefits of the disclosure in order that the description that follows may be better understood. Additional features, advantages, solutions, and benefits of the disclosure will be described in the following. It should be appreciated by those skilled in the art that this disclosure may be readily utilized as a basis for modifying or designing other structures and related operations for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions and related operation do not depart from the teachings of the disclosure as set forth in the appended claims. The novel features, together with further objects and advantages, will be better understood from the following description when considered in connection with the accompanying Figures. It is to be expressly understood, however, that each of the Figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a conventional bolt on rear tube assembly according to an aspect of the disclosure;

FIG. 2 is a top view of a conventional bolt on rear tube assembly according to an aspect of the disclosure;

FIG. 3 is a perspective view of an electrical drive system according to an aspect of the disclosure;

FIG. 4 is a top view of an electrical drive system according to an aspect of the disclosure;

FIG. 5 is a side view of an electrical drive system according to an aspect of the disclosure;

FIG. 6 is a perspective view of an electrical drive system according to an aspect of the disclosure;

FIG. 7 is a diagram view of an electrical drive system according to an aspect of the disclosure;

FIG. 8 is a schematic view of an electrical drive system according to an aspect of the disclosure;

FIG. 9 is a schematic view of an operation of an electrical drive system according to an aspect of the disclosure; and

FIG. 10 is a diagram view of an operation of an electrical drive system according to an aspect of the disclosure.

DETAILED DESCRIPTION

The disclosure described herein is directed to different aspects of an electrical drive system configured for use with heavy machinery, including a machine scraper. The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. These descriptions include specific details for the purpose of providing a thorough understanding of the various concepts. It will be apparent, however, to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components may be shown in block diagram form to avoid obscuring such concepts. As described herein, the use of the term “and/or” is intended to represent an “inclusive OR”, and the use of the term “or” is intended to represent an “exclusive OR”.

The disclosure is described herein with reference to certain aspects, iterations, embodiments, and examples but it is understood that the disclosure can be embodied in many different forms and should not be construed as limited to the aspects set forth herein. In particular, the disclosure is described herein regarding a machine scraper used for earth moving, but it is understood that the disclosure can be configured for operation with other heavy machinery.

Although the terms first, second, etc. may be used herein to describe various elements, components, or phases, these elements, components, and phases should not be limited by these terms. These terms are only used to distinguish one element or component from another. Hence, a first element discussed herein could be termed a second element without departing from the teachings of the present application. It is understood that actual systems or fixtures embodying the disclosure can be arranged in many ways with many more features and elements beyond what is shown in the drawings. For the same or similar elements or features, the same reference numbers may be used throughout the disclosure.

It is to be understood that when an element or component is referred to as being “on” another element or component, it can be directly on the other element or intervening elements may also be present. Furthermore, relative terms such as “between”, “within”, “below”, and similar terms, may be used herein to describe a relationship of one element or component to another. It is understood that these terms are intended to encompass different orientations of the disclosure in addition to the orientation depicted in the Figures unless expressly claimed.

Aspects of the disclosure may be described herein with reference to illustrations that are schematic illustrations. As such, the actual thickness of elements can be different, and variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances are expected. Thus, the elements illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region of a device and are not intended to limit the scope of the disclosure.

With reference to the Figures aspects of an electrical drive system 10 for a machine scraper 12 connected to and/or hitched to a vehicle such as a tractor 14 is shown according to the disclosure. Although the present disclosure describes use with the tractor 14, in alternatives the vehicle 14 is also contemplated to comprise a dozer, a crawler, a ridge frame hauler, a skid loader, a skid steer, other towing machinery, or the like.

While various types and forms of the machine scraper 12 are contemplated, as depicted, the machine scraper 12 comprises a bolt on rear tube 16 or BORT having a rearward drive housing 17, a bowl 18, an ejector 20, an apron 22, a scraper blade 24 having a cutting edge 26, a neck 28 (such as a goose neck, tongue, or the like), and a hitch or connection member 30. More particularly, the bolt on rear tube 16 connects to a first side 32 of the bowl 18 and the neck 28 and the hitch 30 connect on a second side 34 of the bowl 18. The bolt on rear tube 16 connects to the bowl 18 by aligning a first bolt pattern 36 on at least one mount plate 38 of the bolt on rear tube 16 with a second bolt pattern 40 on the first side 32 of the bowl 18 and inserting one or more connection members, such as a bolt and nut 42 through the first bolt pattern 36 and the second bolt pattern 40 to join the bolt on rear tube 16 and the bowl 18 together. In other aspects, the bolt on rear tube 16 is fixedly attached to the bowl 18, such as by way of welding or monolithic manufacture.

A conventional embodiment of the machine scraper 12, i.e. those without the electrical drive system 10, further comprises the bolt on rear tube 16 having a rear push block 44 on a side 46 opposite the connection to the bowl 18 that is configured to be engaged by a bulldozer 48 (not shown) during a push dozer as previously described herein. The rearward drive housing 17 is positioned within or on the bolt on rear tube 16 and is the location in which the electrical drive system 10 is housed in non-conventional aspects according to the present invention. The machine scraper 12 conventionally comprises a dummy axle 52 that extends through the rearward drive housing 17 with a wheel 54 and a tire 56 connected at opposing ends 58 of the dummy axle 52.

The hitch 30 of the machine scraper 12 connects to the tractor 14. The tractor 14 comprises a frame 60 having a cab 62 for an operator to operate the tractor 14 and the machine scraper 12, and a tractor control system 64.

The tractor control system 64 in one aspect of the present disclosure comprises one or more sensors 66, which can include a tractor speed sensor 68 configured to sense the speed registered by the tractor 14 but not the actual ground speed the tractor 14 is travelling, a selected or commanded gear sensor 70 configured to sense a gear 72 that the tractor 14 is currently in, an output shaft speed sensor 74 configured to sense the speed of an output shaft 76, an engine torque sensor 78 configured to sense a torque output of an engine 80 of the tractor 14, an engine speed sensor 82 configured to sense a speed of the engine 80, a coolant temperature sensor 84 configured to sense a coolant temperature of the engine 80, an oil pressure sensor 86 configured to sense an oil pressure of a hydraulic system 88 of the tractor 14, and/or an estimated ground speed sensor 90 configured to sense or calculate an actual ground speed the tractor 14 is travelling. In some aspects, the estimated ground speed sensor 90 is configured to provide or calculate an actual ground speed that does not account for environmental changes such as ground consistency and incline, as well as wheel or track slip of the tractor 14. The tractor control system 64 is configured to transmit sensed data or information from the one or more sensors 66 to the electrical drive system 10 as described further herein, which in some aspects is accomplished by way of a controlled area network (CAN) 92, but in other aspects is provided in any number of ways including WiFi, Bluetooth, near field communication, and a wired connection.

In another aspect of the present disclosure, the electrical drive system 10 replaces the dummy axle 52 of a conventional embodiment of the machine scraper 12. In other aspects, the electrical drive system 10 comprises one or more batteries or battery packs 94, an electrical drive device 96, a power control system 98 that in some aspects comprises a power conditioning circuit 99 configured to transition between AC and DC power, and a powered axle or driven axle 100. In yet other aspects, the battery packs 94 have a DC/DC convertor 95 (not shown) in order to step up voltage from the battery pack 94 during operation of the electrical drive system 10 acting as a motor.

The battery pack 94 in one aspect is configured to store electric power and to provide electric power to the electrical drive device 96 in a motor function. In another aspect, the battery pack 94 is configured to be rechargeable by a wired connection or a regenerative cycle of the electrical drive system 10 as described further herein. In still further aspects, the battery pack 94 is configured to be replaceable or swappable with a different battery pack 94 to allow for a quick replacement should the battery back 94 run out of power during operation and regeneration is not possible or insufficient to complete the necessary work.

The electrical drive device 96 is in electrical communication with the battery pack 94. The electrical drive device 96 in another aspect of the invention is configured to operate in conjunction with the power control system 98 acting as both a motor and a generator. When acting as a motor, the electrical drive device 96 and power control system 98 are configured to provide power to the powered axle 100 to rotate a final drive 53, wheels 54, and tires 56 of the machine scraper 12. When acting as a generator, the electrical drive device 96 and power control system 98 are configured to generate power through the passive rotation of the powered axle 100, which is stored in the battery pack 94. As disclosed further herein, the transition between the electrical drive device 96 acting as a motor and a generator is controlled by the power conditioning circuit 99 switching between providing DC and AC power based on sensed and received information received from the tractor control system 64 and a scraper control system 102. The power control system 98 in other aspects is configured to transmit information to the tractor control system 64 and/or the scraper control system 102 by way of a communication device such as a CAN 92, but in other aspects is provided in any number of communicative ways including WiFi, Bluetooth, near field communication, a wired connection, or the like.

In some aspects, the electrical drive system 10 consists of only a single electrical drive device 96. This provides the unique benefit of obviating the need for a differential steering program 103 (not shown) that would otherwise be necessary to complete powered turns when multiple electrical drive devices 96 are present.

The electrical drive device 96 is connected to a differential 104 of the powered axle 100. Connected to opposing sides 106 of the differential 104 are one of a pair of spindles 108, respectively. In some aspects, one or more spacers 110 are positioned between the differential 104 and each of the pair of spindles 108 to adjust the width the powered axle 100 extends in perpendicular or substantially perpendicular relation to the length by which the bolt on rear tube 16 extends from the side 46 of the bolt on rear tube 16 and the bolt on rear tube 16 connection to the bowl 18. The spacers 110 extend the width of the powered axle 100 to the standard width of the machine scraper 12 as well as to adjust the side elevation, stability, and wheel track. Accordingly, the number of spacers 110 is adjustable to optimize performance. Attached to each of the pair of spindles 108 is the final drive 53, the wheel 54, and the tire 56.

In other aspects of the present invention, an electrical drive system 10 is positioned and arranged within the rearward drive housing 17 to provide a variety of advantages. In one aspect, the electrical drive system 10 is mounted to the powered axle 100 within the rearward drive housing 17 of the bolt on rear tube 16, which provides the unique benefit of providing a weight distribution offset that increases torque to push the machine scraper 12. Additionally, less weight transfer occurs in this position when the electrical drive system 10 is operating. This in turn provides the advantage of reducing load shock to the powered axle 100 and component strain and improving the life of the power train as well as improving traction throughout operation as wheel slip is reduced. In still further aspects the powered axle 100 is positioned in the same or substantially the same position to allow for the electrical drive system 10 to retrofit into a pre-existing bolt on rear tube 16 of the machine scraper 12. This further provides the benefit of maintaining the same fore and aft positions of the powered axle 100 as compared to the dummy axle 52. Still further, this provides the advantage of the center of gravity, weight distribution, and cut force changing after a retrofit.

In other aspects, the battery pack 94 is positioned over a centerline of the powered axle 100 extending axially along the length and diameter of the powered axle 100. In this position, the electrical drive system 10 is readily accessible for inspections, repairs, and replacements from a top 112 of the bolt on rear tube 16 above the rearward drive housing 17. This in turn decreases the down time related to inspections, repairs, and replacements of components of the electrical drive system 10.

In one aspect of the present invention, the battery pack 94 is positioned immediately above the electrical drive device 96. In this position, the length of one or more cables 114 connecting the battery pack 94 to the electrical drive device 96 is limited, which in turn reduces the costs associated with the cables 114 while also limiting ampacity, internal resistance, and the likelihood of the cables 114 being severed as the voltage is positioned close to where it is acting—in turn, increasing the operational safety of using the electrical drive system 10.

In yet other aspects, the electrical drive device 96 is directly connected to or coupled to the differential 104. In this way, the need to shift gears is eliminated and further provides the unique advantage of allowing the electric drive device 96 to be engaged to act as a motor at any time commanded by the power control system 98 to provide additional force or drive on the fly or nearly immediately. In other aspects, the electrical drive device 96 and the power control system 98 are positioned to the rear of the differential 104 and behind the center line of the powered axle 100. In this position, the electrical drive device 96 and the power control system 98 create a movement about the powered axle 100 so that the machine scraper 12 will roll to the back of the machine scraper 12. Additionally, a movement is created about the hitch 30 to lift up on the hitch 30 during operation as a motor. This contrasts with rolling weight of the machine scraper 12 onto the tractor 14 as in the case in conventional arrangements. In doing so, the vertical load on the hitch 30 is limited, which reduces the wear and tear on the tractor 14. This benefit is maximized when the bowl 18 of the machine scraper 12 is filled and the tractor 14 is transporting the load. The above described positioning and arrangements each individually and in combination provide the advantage of increasing the push force behind the cutting edge 26 of the scraper blade 24 during a cut.

In some aspects, the electrical drive system 10 further comprises the scraper control system 102 but in other aspects the scraper control system 102 is separate from the electrical drive system 10. The scraper control system 102 is configured to sense and to transmit sensed data or information from the one or more sensors 66 to the electrical drive system 10. In particular aspects, the scraper control system 102 comprises one or more sensors 66, which can include an apron sensor 116 configured to sense and control the position of the apron 22, a cutting edge sensor 118 configured to sense and control the position of the scraper blade 24 and angle of the cutting edge 26, a load sensor 120 configured to sense the weight of a load carried in the bowl 18, and a cooling system sensor 122. The scraper control system 102 in other aspects is configured to transmit information to the electrical drive system 10 and/or the tractor control system 64 by way of a CAN 92, but in other aspects is provided in any number of ways including WiFi, Bluetooth, near field communication, and a wired connection.

In other aspects of the present invention, the bolt on rear tube 16 comprises the rear push block 44 but in other aspects the rear push block 44 is excluded. To further allow for retrofit and rapid replacement in the event of the electrical drive system 10 running out of power, the bolt on rear tube 16 further comprises the first bolt pattern 36 to permit the bolt on rear tube 16 to be retrofitted or replaced with a fully charged replacement of the electrical drive system 10 in a different bolt on rear tube 16.

During an exemplary use of the electrical drive system 10, the operation of the present invention is separated into a first phase or empty phase 200, a second phase or cutting/loading phase 202, a third phase or transport phase 204, and fourth phase or fill/dump phase 206.

Prior to undertaking the first phase for the first time, the battery pack 94 is fully charged—most commonly during an overnight process where the machine scraper 12 is not in use for an extended period. This process is repeated at the end of use each day as needed.

During the first phase 200 the bowl 18 of the machine scraper 12 is empty and the tractor 14 is pulling the machine scraper 12. The electrical drive device 96 in the first phase 200 is acting as a generator except for certain circumstances and aspects detailed further herein. In this way, the powered axle 100 rotates passively without the electrical drive device 96 providing power. The speed of the tractor 14 during the first phase 200 is commonly the highest in comparison to the other phases.

Upon reaching a location to complete a cut, the second phase 202 begins. The operator causes the tractor 14 to change the gear 72, reduce the speed of the tractor 14, open the apron 22, and lower the bowl 18 to put the cutting edge 26 of the scraper blade 24 in contact with the ground. The power control system 98 commands the electrical drive device 96 to act as a motor to provide power to the powered axle 100 to facilitate the cut by working in substantially synchronized operation with the tractor 14 as the tractor 14 and machine scraper 12 cut the ground and fill the bowl 18. During the second phase 202, the discharge from the battery pack 94 to the electrical drive device 96 is highest except for certain circumstances and aspects detailed further herein.

After the cut is completed, the bowl 18 is raised and the apron 22 is closed at the start of the third phase 204. The material collected in the bowl 18 is then transported to a different location. During transport, the electrical drive system 10 continues to operate as a motor, but the power provided to the electrical drive device 96 is reduced and likewise, the discharge from the battery pack 94 is lessened. In some aspects, the discharge from the battery pack 94 is reduced to between 10% and 15%, or alternatively to 7.5% of maximum discharge to or full draw by the electrical drive device 96.

When the other location is reached the fourth phase 206 begins. The bowl 18 remains raised and the apron 22 is up to allow the ejector 20 to move forward to remove the collected material from the bowl 18. During this time, the electrical drive device 96 acts as a generator and does not provide power to the powered axle 100. Rather, as the machine scraper 12 is pulled forward the rotation of the powered axle 100 rotates against the electrical drive device 96 to generate electricity that is stored in the battery pack 94.

The regeneration of electricity to the battery pack 94 continues as the operation cycle returns to the first phase 200. Accordingly, during the first phase 200 and the fourth phase 206, the electrical drive device 96 creates a limited drag on the engine 80 of the tractor 14 to trickle charge the battery pack 94. As a result, the power regeneration of the electrical drive system 10 is approximately (i.e., 99% of) or actually 1:1, such as to provide operation of the machine scraper 12 with the assistance of the electrical drive system 10 during a full day of operation—requiring only a full charge overnight when the machine scraper 12 is not in use.

In some aspects of the present invention, the electrical drive device 96 is configured to provide regenerative braking. In certain aspects, regenerative braking is accomplished by drawing down the discharge of power to the powered axle 100 or the tractor 14 braking with the latter being sensed by the tractor control system 64 and transmitted to the electrical drive system 10 to change the electrical drive device 96 to act as a generator and apply a drag on the tractor 14 while assisting in braking. In certain aspects, the detection of the tractor 14 braking is accomplished by way of receiving a signal from the tractor control system 64 and in other aspects the determination that the tractor 14 is braking is accomplished by the power control system 98 receiving or otherwise determining that a brake light 123 is receiving power to illuminate. This further provides the advantage of eliminating the need for the machine scraper 12 having air, hydraulic, or dry brakes.

As described, the electrical drive system 10 harnesses energy for regeneration during the typical operation that would otherwise be lost. Through regeneration, the monetary investment in and the size of the battery pack 94 is limited. In this way, regeneration of the battery pack 94 occurs whenever the powered axle 100 is not being provided power by the electrical drive device 96. In another aspect of the present invention, the power control system 98 is configured to stop regeneration when the battery pack 94 is at capacity. In other aspects, the power control system 98 has a buffer 124 (not shown) configured into the regeneration cycles to avoid exceeding capacity by only permitting regeneration to a capacity below the maximum capacity of the battery pack 94. By limiting regeneration, the need for a super capacitor, a costly component, is eliminated.

The transition between the electrical drive device 96 acting as a generator or a motor is controlled by the power control system 98 based on limiting conditions and characteristics of the tractor 14 and/or machine scraper 12. In further aspects, the power control system 98 is configured to command the electrical drive device 96 to act as a motor in order to match the actual ground speed of the machine scraper 12 to that of the tractor 14. In still further aspects, the power control system 98 is configured to command the electrical drive device 96 to act as a motor in order to match the actual ground speed of the machine scraper 12 to that of the tractor 14 under predefined conditions and characteristics of the tractor 14 and/or machine scraper 12.

In an aspect of the present invention, the tractor control system 64 transmits one or more of the speed, commanded gear, output shaft speed, engine torque, calculated ground speed, error faults, and/or actual ground speed sensed or determined by the one or more sensors 66 of the tractor 14 to the electrical drive system 10. In other aspects, the power control system 98 is configured to store defined characteristics of the tractor 14 or such information or data is transmitted to the electrical drive system 10 by the tractor control system 64. The predefined characteristics of the tractor 14, in certain aspects, comprise one or more of an axle ratio, a rolling radius of the wheel or track of the tractor. In further aspects, the power control system 98 is conditioned to store defined characteristics of the machine scraper 12, including, in certain aspects, one or more of an axle ratio or a rolling radius of the tires 56. In still further aspects, the electrical drive system 10 or the tractor 14 further comprises the ground speed sensor 90, such as a radar gun, to sense and/or determine the actual ground speed of the tractor 14 and/or machine scraper 12.

In some aspects of the electrical drive system 10, the electrical drive device 96 is commanded by the power control system 98 to function as a motor when the tractor 14 is in a predefined gear 72 and travelling at a predefined speed. In still further aspects, the predefined speed varies based on the predefined gear 72 of the tractor 14. By way of example, the electrical drive system 10 is configured to operate as a motor only when the gear 72 of the tractor 14 is in 4th to 6th gear and travelling between 4 and 7 miles per hour as these are commonly the gears 72 and speeds at which the second phase or cutting/loading phase 202 and third phase or transport phase 204 take place in. In further aspects, the electrical drive system 10 is configured to command the electrical drive device 96 to operate as a motor to rotate the powered axle 100 to match the actual ground speed of the tractor 14, which in some aspects is accomplished by adjusting the output of the voltage output of the electrical drive device 96. In still further objects, the electrical drive device 96 will not be commanded to act as a motor and/or will adjust the amperage output if the current torque of the tractor 14 is insufficient to require activation as a motor and/or will increase the output of the electrical drive device 96 as additional torque is required. The above aspects alone or in conjunction, provide the unique benefits of discharging electricity only under such conditions and characteristics that require the electrical drive system 10 to facilitate the operation of the machine scraper 12 and tractor 14, as well as eliminating the machine scraper 12 from pushing the tractor 14 more than is needed to match the actual ground speed of the tractor, and from causing the machine scraper 12 to impose a drag on the tractor 14 beyond the minimal drag imposed for regeneration as disclosed herein.

In other aspects, the activation of the electrical drive device 96 to act as a motor under predefined conditions and characteristics provides the operator the ability to shift into the predefined gear 72 and adjust the speed of the tractor 14 to the predefined speed to activate the electrical drive device 96 to act as a motor. This is beneficial, as the tractor 14 may encounter troublesome terrain, such as obstacles or incline, outside of the cutting/loading phase 202. In yet another aspect, the power control system 98 is configured to discharge generated energy that could result in harm to the battery pack 94 in the event of the tractor 14 rapidly changing gear 72 and/or speed.

In another aspect of the present invention, the tractor 14 further comprises an override control 126 to allow an operator to manually activate or deactivate the electrical drive system 10. In other aspects, the electrical drive system 10 is only activated or deactivated to act as a motor under the predefined conditions and characteristics, without the availability for manual override by the operator, which reduces problems caused by operator intervention with the electrical drive system 10.

By way of example, FIG. 10 shows one possible configuration of the interaction between the electrical drive system 10 and the tractor 14. At 300, the electrical drive system 10 is powered on and operation of the tractor 14 begins. During operation of the tractor 14, at 302, data and/or messages are transmitted from the tractor control system 64 to the electrical drive system 10. At 304, the electrical drive system 10 determines whether the data and/or messages received from the tractor control system 64 are needed to alter operation of the electrical drive system 10. If the data and/or message is not needed (at 304A) the data and/or message is disregarded 305. Alternatively, at 304B, the data and/or message is needed, the power control system 98 determines at 306 whether the electrical drive device 96 should act as a motor or a generator based on the data and/or message from the tractor control system 64 in conjunction from data and/or messages received from the control system (at 308). Based on the determination at 306, the power control system 98 sends a command to the power conditioning circuit 99 to discharge power from the battery pack 94 to the electrical drive device 96 based on the conditions and characteristics of the tractor 14 discussed herein, or whether the electrical drive device 96 should be charging the battery pack 94. At 310, the power control system 98 determines that the electrical drive device 96 should act as a motor and power from the battery pack 94 is discharged to the electrical drive device 96 to match the actual ground speed of the tractor 14 and/or provide additional torque to complete work, such as a cut, at 312. Alternatively, at 310, the power control system 98 determines that the electrical drive device 96 should act as a generator to charge the battery pack 94. In doing, the power control system 98 determines whether the battery pack 94 is fully charged or not—or alternatively, whether the charged capacity of the battery pack has reached the buffer 124 at 314. At 314A, the power control system 98 determines that the battery pack 94 is not charged and commands the electrical drive device 96 to act as a generator to generate power to be stored in the battery pack 94 at 316. Alternatively, at 314B, the power conditioning circuit determines that the battery pack 94 is fully charged and/or at the buffer 124 and commands the electrical drive device 96 to fully disengage from the powered axle 100 to allow a freewheel of the powered axle 100 at 318. In yet another alternative, the power conditioning circuit determines that the battery pack 94 is fully charged and/or at the buffer 124 and commands the electrical drive device 96 to operate in a low torque mode to supply only the amount of torque necessary to overcome the rolling resistance of the drivetrain and/or wheels 54. In this way, the electrical drive system 10 provides charging when commanding the power control system 98 to function as a generator, provides a minimal discharge when commanding the power control system 98 to provide a low torque to simply follow the tractor 14, or provide a discharge necessary to assist with a cut in accordance with the various aspects described herein.

In other aspects of the present invention, the electrical drive system 10 is powered exclusively by or supplemented with an engine 128 and an electrical generator 130 on the machine scraper 12. In such aspects, the engine 128 and the electrical generator 130 are operated to provide power to the electrical drive device 96 directly and/or to the battery pack 94.

For a firmware and/or software implementation, the methodologies may be implemented with modules (e.g., procedures, functions, routines and so on) that perform the functions described herein. A machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software codes may be stored in a memory and executed by a processor unit. Memory may be implemented within the processor unit or external to the processor unit. As used herein, the term “memory” refers to types of long term, short term, volatile, nonvolatile, or other memory and is not to be limited to a particular type of memory or number of memories, or type of media upon which memory is stored. If implemented in firmware and/or software, the functions may be stored as one or more instructions or code on a computer-readable medium. Examples include computer-readable media encoded with a data structure and computer-readable media encoded with a computer program. Computer-readable media includes physical computer storage media. A storage medium may be an available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, solid state or other magnetic storage devices, or other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer; disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. In addition to storage on computer readable medium, instructions and/or data may be provided as signals on transmission media included in a communication apparatus. For example, a communication apparatus may include a transceiver having signals indicative of instructions and data. The instructions and data are configured to cause one or more processors to implement the functions outlined in the claims.

Therefore, an electrical drive system 10 has been provided that eliminates the need for a push dozer methodology of operation; reduces operational costs of heavy machinery, including a machine scraper and those towed by a tractor; reduces the number of machines required to complete a project; reduces the number of operators required to complete a project; retrofits to an existing machine scraper; retrofits to an existing bowl of a machine scraper; increases the torque of a towed machine scraper during a cut and transport; increases the operational life of a machine scraper and a tractor; operates for a full workday without need for a plugged charge; matches the actual ground speed of a tractor with the ground speed of a machine scraper; provides consistent power, including behind the cutting edge; reduces negative environmental impacts of machine scraper operation; and improves upon the art.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. For instance, using a tracked system instead of a wheeled system for movement. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The various illustrative logical blocks, and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the disclosure may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, a removable disk, a CD-ROM, solid state storage, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal. In yet other aspects, the processor can be remote to the storage medium and accesses the storage medium through a linked connection.

In one or more exemplary designs, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, solid state, or any other medium that can be used to carry or store specified program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

In the present disclosure, the processor may serve as a structure for computer-implemented functions as described herein because the function(s) described in one or more aspects of the present disclosure are coextensive with the processor itself. Further, such a processor may serve as structure for functions that may be achieved by a general purpose computer without special programming, because the coextensive functions include receiving data, storing data, processing data, etc. Further, the present disclosure are removed from the abstract, and do not merely limit the use of an abstract idea to a particular technological environment. The present disclosure expands basic building blocks beyond the mere sum of the parts, at least for the reason that the present disclosure provides faster, more consistent, and more reliable results than obtainable with current methods and devices.

From the above discussion and accompanying figures and claims it will be appreciated that the electrical drive system 10 offers many advantages over the prior art. Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions, modifications, and alterations can be made herein without departing from the technology of the disclosure as defined by the appended claims. The scope of the present application is not intended to be limited to the particular configurations of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification only expressly stated otherwise. As one of ordinary skill in the art will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding configurations described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. 

What is claimed is:
 1. An electrical drive system, comprising: a battery pack; an electrical drive device in electrical communication with the battery pack; a power control system connected to the electrical drive device; a power conditioning circuit connected to the electrical drive device and the power control system; a powered axle connected to the electrical drive device; and wherein the power control system and the electrical drive device are configured to operate as a generator through passive rotation of the powered axle to create power that is stored in the battery pack; wherein the electrical drive device and the power control system are configured to operate as a motor by providing power stored in the battery pack to the powered axle; wherein the electrical drive device and the power control system are configured to operate in an empty phase, a cutting/loading phase, a transport phase, and a fill/dump phase.
 2. The electrical drive system of claim 1 further comprising a tractor control system and a scraper control system; wherein the tractor control system and the scraper control system are configured to transmit information from at least one sensor with the power control system; and wherein the power control system is configured to command the electrical drive device to operate as a generator and a motor based on information received from the tractor control system and the scraper control system.
 3. The electrical drive system of claim 2 further comprising the tractor control system having the at least one sensor selected from a group consisting of a tractor speed sensor configured to sense a speed registered by a tractor but not an actual ground speed, a commanded gear sensor configured to sense a gear that the tractor is currently in, an output shaft speed sensor configured to sense the speed of an output shaft of the tractor, an engine torque sensor configured to sense a torque output of an engine of the tractor, an engine speed sensor configured to sense a speed of the engine of the tractor, a coolant temperature sensor configured to sense a coolant temperature of the engine of the tractor, an oil pressure sensor configured to sense an oil pressure of a hydraulic system of the tractor, an estimate ground speed sensor that is configured to calculate an actual ground speed of the tractor that does not account for environmental changes and slippage, and an actual ground speed sensor configured to determine the actual ground speed of the tractor.
 4. The electrical drive system of claim 2 further comprising the scraper control system having the at least one sensor selected from a group consisting of an apron sensor configured to sense and control a position of an apron of a machine scraper, a cutting edge sensor configured to sense and control a position of a scraper blade of the machine scraper and an angle of a cutting edge of the scraper blade, a load sensor configured to sense a weight of a load carried in a bowl of the machine scraper, and a powertrain cooling system sensor.
 5. The electrical drive system of claim 1 further comprising a differential, a final drive, a wheel, and a tire connected to the powered axle; wherein one or more pairs of spindles are connected to opposing sides of the differential.
 6. The electrical drive system of claim 5 further comprising a spacer positioned between the differential and at least one of the pair of spindles, wherein the spacer is configured to adjust a width of the powered axle.
 7. The electrical drive system of claim 1 further comprising the powered axle extending through a rearward housing of a bolt on rear tube; wherein the battery pack, the electrical drive device, the power control system, and the power conditioning circuit are mounted to the powered axle within the rearward housing.
 8. The electrical drive system of claim 7 wherein the powered axle is retrofitted to the bolt on rear tube in a position and replacement of a dummy axle.
 9. The electrical drive system of claim 7 wherein the battery pack is positioned over a centerline of the powered axle extending axially along a length of the powered axle.
 10. The electrical drive system of claim 7 further comprising at least one cable connecting the battery pack to the electrical drive device; wherein the battery pack is positioned immediately above the electrical drive device.
 11. The electrical drive device of claim 7 further comprising a differential directly coupled to the electrical drive device.
 12. The electrical drive device of claim 11 wherein the electrical drive device and the power control system are positioned to a rear of the differential and behind a centerline of the powered axle extending axially along a length of the powered axle.
 13. The electrical drive system of claim 7 further comprising a machine scraper having a bowl connected to the bolt on rear tube; the bowl having an apron, an ejector, and a scraper blade having a cutting edge; and the machine scraper connected to a tractor.
 14. The electrical drive system of claim 13 wherein the power control system is configured to command the electrical drive device to operate as a motor to provide power to the powered axle to match a speed of the machine scraper to an actual speed of the tractor.
 15. The electrical drive system of claim 13 wherein the electrical drive device and the power control system are configured to operate as a motor under a predefined speed and a predefined gear of the tractor, wherein the predefined speed varies based on the predefined gear.
 16. The electrical drive system of claim 13 wherein the power control system is configured to command the electrical drive device to operate in the empty phase, the cutting/loading phase, the transport phase, and the fill/dump phase based on a condition selected from a group consisting of a condition of the tractor and a condition of the machine scraper.
 17. The electrical drive system of claim 16 wherein when the power control system and electrical drive device operate in the empty phase and the fill/dump phase the powered axle rotates without the electrical drive device providing power and the electrical drive device operates as a generator by putting drag on an engine of the tractor by way of the powered axle to charge the battery pack; and wherein when the power control system and electrical drive device operate in the cutting/loading phase and the transport phase the power control system commands the electrical drive device to operate as a motor to provide power to the powered axle.
 18. The electrical drive system of claim 17 wherein the condition of the tractor is selected from a group consisting of an actual speed of the tractor, a gear of the tractor, an output shaft speed of the tractor, an engine torque of the tractor, a calculated speed of the tractor, and an error fault of a tractor control system of the tractor.
 19. The electrical drive system of claim 17 wherein a discharge from the battery pack is higher in the cutting/loading phase than the transport phase.
 20. The electrical drive system of claim 1 wherein the power conditioning circuit is configured to determine that the battery pack is at a buffer and to command the electrical drive device to operate in a low-torque mode to supply only an amount of torque necessary to overcome a rolling resistance of a wheel. 